1. Field
Embodiments of the disclosure generally relate to fluid cylinder blocks that are utilized in pressurized fluid delivery systems to transfer high volumes of fluids at extreme pressures and, in particular, to a fluid cylinder block having one or more stress distributing joints.
2. Description of the Related Art
Pressurized fluid delivery systems which include fluid cylinder blocks for transferring fluids at high pressures are used in multiple industries. One example where such systems are used includes the oil and gas industry where high pressure fluid reciprocating pumps, such as multiplex plunger pumps, are commonly used. These types of pumps have a fluid end that includes valves, pistons, liners, among other components, that are driven by a power end that converts the rotation of a drive shaft to the reciprocating motion of the pistons in the fluid end. The fluid end typically includes a fluid cylinder block having at least three bores that intersect at a junction, and at least two of the bores share a common axis. The pumps facilitate pumping at rates of up to 100 bbl/minute, and are capable of creating variable pressures, e.g., between negative pressures during suction to a discharge pressure of about 1,000 pounds per square inch (psi), or more. This variable pressure may occur at frequent intervals (e.g., about every fifth of a second for a pump operating at 300 strokes per minute). The fluid end of the fluid cylinder blocks frequently has a short service life as the oscillating pressures cause the fluid cylinder block to crack and fail due to cyclic fatigue stress.
Numerous attempts to alleviate stresses in fluid cylinder blocks have been attempted. One such attempt includes completely offsetting the axis of one bore relative to the axis of other bores. However, completely offsetting the bores creates less than ideal flow dynamics in the fluid end. Complete offsetting also complicates servicing of the fluid end since internal valves and other internal components are accessed via the inside of the bores. Thus, introducing additional bends or turns between bores complicates servicing. In addition, offsetting the bores may minimize use of standard internal components resulting in manufacture and/or purchase of customized components. This increases the cost of the fluid end considerably.
Therefore, there exists a need for a fluid cylinder block that resists stresses.